Illegitimi non carborundum
Illegitimi non carborundum is a mock-Latin aphorism meaning "Don't let the bastards grind you down". Carborundum, also known as silicon carbide, is an industrial abrasive material, but its name resembles a Latin gerundive.
The phrase originated during World War II and is attributed to British army intelligence. It was a motto of US Army general "Vinegar" Joe Stillwell and was further popularized in the US by 1964 presidential candidate Barry Goldwater. It is also the first line of the Harvard fight song Ten Thousand Men of Harvard, and a wooden plaque bearing the phrase sits prominently on the desk of U.S. House of Representatives Speaker John Boehner.
There are a number of versions for the phrase referenced in popular culture.
The phrase originated during World War II. Lexicographer Eric Partridge attributes it to British army intelligence very early in the war (using the plural dative/ablative illegitimis). The phrase was adopted by US Army general "Vinegar" Joe Stillwell as his motto during the war. It was later further popularized in the US by 1964 presidential candidate Barry Goldwater.
The phrase is also used as the first line of one of the extra cod latin verses added in 1953 to an unofficial school song at Harvard University: Ten Thousand Men of Harvard. This, the most frequently played Fight song of the Harvard Marching Band, is, to some extent, a parody of more solemn school songs like "Fair Harvard thy sons to your Jubilee throng" etc. The first verse goes:
- Illegitimum non carborundum;
- Domine salvum fac.
- Illegitimum non carborundum;
- Domine salvum fac.
- Gaudeamus igitur!
- Veritas non sequitur?
- Illegitimum non carborundum—ipso facto!
There are many variants of the phrase, such as
- Noli illegitimi carborundum
- Nil illegitimi carborundum
- Non illegitimis carborundum
- Illegitimi nil carborundum
- Nil bastardo carborundum
- Nolite te bastardes carborundorum
- Nil carborundum ab illegitimati
- Illegitimis non carborundum
- Nil illegitimo in desperandum carborundum
- Nil carborundum illegitamae
- Nolite Illegitimos Conterere Vos
- Non carborundum bastardum
None of these variants is 'legitimate' Latin any more than the original. Carborundum is a noun and not a gerundive of any verb (although it does look like a gerundive). Also 'the bastard' in Latin is spurius (another Latin word for bastard is nothus, but it is very uncommon). The two most common variations translate as follows: illegitimi non carborundum = the unlawful are not silicon carbide, illegitimis non carborundum = the unlawful don't have silicon carbide.
"Bastards" is often used in English as a generic derogatory term, not necessarily relating to the marital status of one's parents.
Use as a motto
- "E-1 Vikings" - Echo Company, First Regiment, United States Corps of Cadets, United States Military Academy
- "F2 Zoo" – Foxtrot Company, Second Regiment, United States Military Academy
- The U.S. submarine USS Tunny (SSN-682)
- The weekly Alaskan newspaper the Nome Nugget
- Whitehorse Star, newspaper in the capital of the Yukon Territory
- University of Idaho Navy ROTC Drill Team
- The comic strip Odd Bodkins
- U.S. Air Force 490th Missile Squadron "Farsiders", Malmstrom AFB, MT
- US Army Special Forces 2nd Battalion, 1st Special Forces Group (Airborne), Joint Base Lewis-McChord, Washington
- UK Royal Air Force, Nimrod Line Squadron
- Informal motto of The Fletcher School of Law and Diplomacy
- Used by RCPFA members in response to unfounded allegations against their club.
In popular culture
- Nil Carborundum, title of a 1962 play and TV comedy by Henry Livings.
- Nolite te bastardes carborundorum, in The Handmaid's Tale (1985) by Margaret Atwood.
- Illegitimi non carborundum, in Lucifer's Hammer (1977) by Larry Niven and Jerry Pournelle
- Nil illegitimo carborundum is a maxim credited to the fictional philosopher Didactylos in Terry Pratchett's Small Gods.
- Non Illegitimus Carborundum is the school motto of the fictional girl's school St. Trinian's, appearing on the school's coat of arms.
- Illegitimis non Carborundum is printed on a banner in the artwork for The Toasters' 7th studio album Don't Let the Bastards Grind You Down and Dee Snider's solo album Never Let the Bastards Wear You Down.
- Nil carborundum illegitimus is a phrase (sometimes abbreviated N.C.I) used by Kath Lewis in Donald Jack's novels Three Cheers for Me and That's Me in the Middle.
- Nil carborundum illegitimis is said by Landon Kettlewell in Cory Doctorow's Makers 
- "Don't let the bastards grind you down" last phrase of Motorhead "(Don't Let 'Em) Grind Ya Down" song from Iron Fist album.
- "So don't let the bastards grind you down" is the chorus of the song Acrobat, by U2.
- Inscribed on a watch given by Michael Mates MP, to Asil Nadir of Polly Peck fame.
- Mentioned in Rihanna's song "Cheers".
- Mentioned with translation by the Member of Parliament for Twickenham Toby Jessel in the House of Commons of the United Kingdom on June 7, 1993.
- Mentioned in the TV show The OC by Taylor Townsend at the end of her graduation speech. 
- Mentioned by Premier of Newfoundland, Danny Williams in reference to a power deal with Nalcor Energy on February 20, 2009.
- Spoken by Robin Williams at the end of his acceptance speech for the Icon Award at The Comedy Awards 2012.
- "Dont let the bastards grind you down" is the chorus of the song "Epitaph" by the band Hey Rosetta.
- "Illegitimi non carborundum" said by the main character of the Alpha and Omega series by Patricia Briggs.
- Why Do We Say ...?, Nigel Rees, 1987, ISBN 0-7137-1944-3
- Illegitimi Non Carborundum page[dead link], at Santa Cruz Public Libraries ready reference, quoting William Safire, Safire's New Political Dictionary
- Primus V (2012) Ipso facto!. Harvard Magazine, November-December (Accessed April 2013)
- Chambers Murray Latin Dictionary, page 468
- See the discussion in Hugh Rawson, Wicked Words (New York: Crown, 1989), pp. 36f
- Nil Carborundum (TV 1962) – IMDb
- Cory Doctorow. "Makers". Tor Books. Retrieved 2009-07-31.
- Department of the Official Report (Hansard), House of Commons, Westminster. "House of Commons Hansard Debates for 7 Jun 1993". Publications.parliament.uk. Retrieved 2009-07-15.
- Terry Roberts (20th February 2009). "Williams hopes Harper takes a few tips from Obama". TheWesternStar.com. Retrieved 2010-04-15.